remarked upon the irony that this qualifier of veracity often introduces an utter lie;[1] and,

noted that in many cases, actually functions as little more than a vacuous emphatic utterance.[2]

In practice, actually and its synonyms are often used to insinuate that the following is either unusual or contrary to a norm or preceding assumption, or to merely preface an overconfidentopinion contrasting a previous statement or norm (as per 'vacuous emphasis' note above).

This is actually a really beautiful song. (contrasting opinion)

Actually, I'm not from France - I'm from Switzerland. (contrary from assumption)

At the check-out, the cashier actually greeted me for once. (contrary from norm)